Estimation of tea catechin levels using micellar electrokinetic chromatography: A quantitative approach

Chao Ming Liu, Chung Yu Chen, Yang-Wei Lin

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

A simple, inexpensive micellar electrokinetic chromatography (MEKC) method with UV detection was used to determine seven catechins and one xanthine (caffeine) in tea. All the compounds were successfully separated (15 kV) within a 15-min migration period with a high number of theoretical plates (>8.0 × 104) in a running buffer (pH 7) containing 10 mmol l -1 sodium tetraborate, 4 mmol l-1 sodium phosphate, and 25 mmol l-1 SDS. The regression lines of all standard catechins were linear within the range of 0.03-4 μg ml-1. Green tea infused at 95 C for 10 min showed higher levels of catechins (especially epigallocatechin galate, epicatechin gallate, and epicatechin) than tea infused at 80 C. In addition, major differences were observed in the levels of catechins in the first and second infusions (both brewed at 95 C for 10 min). Finally, green tea leaves were infused separately with tap water, deionised water, spring water, reverse osmosis water, and distilled water at 95 C, and the catechin content of the infusions was investigated by the proposed method. In the infusion brewed with tap water, catechins appeared to be epimerisation from the epistructure to the nonepistructure. This epimerisation may take place more readily in tap water than in distilled water owing to the complexity of the ions present in tap water.

Original languageEnglish
Pages (from-to)145-150
Number of pages6
JournalFood Chemistry
Volume150
DOIs
Publication statusPublished - 2014 Jan 1

Fingerprint

Catechin
Tea
flavanols
Chromatography
catechin
tea
tap water
chromatography
Water
epicatechin
green tea
water
reverse osmosis
xanthine
sodium phosphate
epigallocatechin
caffeine
Springs (water)
Xanthine
Deionized water

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Food Science

Cite this

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abstract = "A simple, inexpensive micellar electrokinetic chromatography (MEKC) method with UV detection was used to determine seven catechins and one xanthine (caffeine) in tea. All the compounds were successfully separated (15 kV) within a 15-min migration period with a high number of theoretical plates (>8.0 × 104) in a running buffer (pH 7) containing 10 mmol l -1 sodium tetraborate, 4 mmol l-1 sodium phosphate, and 25 mmol l-1 SDS. The regression lines of all standard catechins were linear within the range of 0.03-4 μg ml-1. Green tea infused at 95 C for 10 min showed higher levels of catechins (especially epigallocatechin galate, epicatechin gallate, and epicatechin) than tea infused at 80 C. In addition, major differences were observed in the levels of catechins in the first and second infusions (both brewed at 95 C for 10 min). Finally, green tea leaves were infused separately with tap water, deionised water, spring water, reverse osmosis water, and distilled water at 95 C, and the catechin content of the infusions was investigated by the proposed method. In the infusion brewed with tap water, catechins appeared to be epimerisation from the epistructure to the nonepistructure. This epimerisation may take place more readily in tap water than in distilled water owing to the complexity of the ions present in tap water.",
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Estimation of tea catechin levels using micellar electrokinetic chromatography : A quantitative approach. / Liu, Chao Ming; Chen, Chung Yu; Lin, Yang-Wei.

In: Food Chemistry, Vol. 150, 01.01.2014, p. 145-150.

Research output: Contribution to journalArticle

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